The present invention relates to parachutes, and more particularly, to a slider which moves down the suspension lines of a gliding parachute to control the deployment thereof and which may be thereafter removed in flight to reduce drag and make the gliding action of the parachute quieter and more efficient.
For many years parachutes have been constructed by sewing a plurality of panels together to define a hemispherical structure when inflated. Some of these dome-like parachutes have incorporated slits, vents or baffles for controlling the flow of air therethrough, both to facilitate deployment and to provide maneuverability. However, these parachutes are adapted primarily for nearly vertical descent, and generally do not permit a load to be guided over substantial horizontal distances to a target landing area.
Recently, gliding parachutes have been developed for sport jumping, fire fighting, and military applications which can be readily manipulated to carry a load over a substantial distance. A typical gliding parachute is preformed and constrained in such a manner that when inflated it will define an airfoil in longitudinal section. When a load is suspended from this type of inflated parachute, the parachute will glide forwardly and its airfoil shape will provide the necessary lift. By controlling the peripheral edges of the gliding parachute, the parachute and the load can be guided in their path of descent to a target many miles away from the drop point.
Much emphasis has been placed on the fabric and rigging configurations of previous gliding parachutes in an effort to approximate, as close as possible, a conventional airfoil shape. This results in maximum lift for a given chute area which in turn provides the maximum glide ratio. In a multi-cell gliding parachute upper and lower fabric canopies are connected by laterally spaced fabric ribs. Suspension lines are connected at their upper ends to the parachute and converge downwardly to a harness or other load supporting structure.
U.S. Pat. No. 4,399,969 discloses a conventional slider arrangement for a gliding parachute. A plurality of suspension lines are connected at their upper ends to the main canopy and extend downwardly in a converging relationship to support the jumper. The lower ends of the suspension lines are connected to the upper ends of four fabric tape risers by connector links. The lower ends of the risers are in turn secured to a harness worn by the jumper. Four separate groups of the suspension lines are threaded through corresponding eyelets in the corners of a rigid, square piece of fabric called a slider. When the parachute is pulled from its deployment bag soon after the jumper leaves the airplane, the main canopy unfolds and begins to fill with air. The slider moves along the suspension lines from a position closer to the main canopy to a position adjacent the jumper's head, gradually restraining the spread of the suspension line as it slides downwardly. The slider thus controls inflation of the main canopy and prevents explosive openings thereof which could rupture fabric or stitching and subject the jumper to a dangerous, forceful jerk.
The conventional slider remains in a generally horizontal position above the head of the jumper as he or she glides through the air. Because of this the slider adds a significant amount of drag, thereby adversely affecting the glide ratio of the parachute. In addition the slider tends to exert forces on the suspension lines causing an undesirable amount of anhedral arc of the main canopy, which further adversely affects the glide ratio of the parachute. Finally, the slider tends to flap in the wind, thereby creating undesirable noise and vibration.